Method for steam heating a food product

ABSTRACT

An apparatus and method of producing a food product is disclosed. The food product is placed inside of an air-tight chamber, in which the food product is to be cooked, wherein steam is generated from a source of water and is introduced into the cooking chamber. The steam heats the inside of the cooking chamber and serves as a heat transfer media to heat the food product as well as a color and flavor transfer media to color and flavor the food product. That is, a flavoring and coloring additive, such as liquid smoke, may be added to the water utilized in generating the steam in order to flavor the food product being cooked. The steam then transfers the flavoring and coloring additive to the food product which condenses on the food product adding flavor and color to the food product.

This application is a Continuation-In-Part of application Ser. No.601,604 filed Feb. 14, 1996, now U.S. Pat. No. 5,662,959 which is aDivisional Application of application Ser. No. 310,756 filed Sep. 26,1994, now abandoned which is a Continuation-in-Part Application of Ser.No. 08/099,418, filed Jul. 30, 1993, now abandoned, which is aContinuation-in-Part application Ser. No. 07/852,785, filed Mar. 17,1992, now U.S. Pat. No. 5,235,903.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to an apparatus and method of producing afood product and in particular an apparatus for enhancing the flavor andcolor of the food product.

2. Background Art

Traditionally, boneless meat products, such as hams, have been cooked inlarge smoke houses to provide additional flavor to the ham. The meatsare usually placed in porous bags which allow the smoke flavor in thesmoke house to penetrate through the bag and into the meat productitself. During the cooking operation, the high temperature in the smokehouse causes the fiber in the meat to shrink inducing the juices in themeat to purge to the surface of the meat. The juice in the meatgenerally consists of water, animal protein, and salt. The watercontained in the juice on the surface of the meat evaporates away duringthe cooking process, which leaves behind a residue of protein and salt.The protein and salt residue is exposed to the high temperatures of thesmoke house which cause the residue to coagulate, thus forming a skin onthe surface of the meat.

The resulting skin on the surface of the meat is usually harder than therest of the cooked meat product. Such a hardened skin is generallyundesirable in taste and appearance to most consumers, especially whenthe meat product is used as a sandwich meat.

One current method of coloring a food product is disclosed in U.S. Pat.No. 4,721,623 to Coffey et al. This reference discloses cooking a meatproduct in an environment sufficiently humid to reduce the evaporationof water contained in a coloring spray which is used within theenvironment. However, this process is to be used in conjunction with ameat product having a skin on its surface. Therefore, the process allowssome evaporation within the environment and does not disclose anenvironment having 100% humidity which prevents any evaporation ofwater. Further, as noted, the coloring process includes spraying themeat product directly with an atomized caramel coloring which merelyresults in coating the food product which can only be sold as a "coloradded" food product.

The use of steam as a heat transfer medium is well known in the priorart. Such steam cooking devices may employ the steam at atmosphericpressure as in U.S. Pat. No. 4,011,805 with convection heat transfer.Steam as the heat transfer medium at substantially atmospheric pressurewith forced convection heat transfer is also known from U.S. Pat. No.4,173,215. In this last patented arrangement, water is introduced intothe bottom of a steam chamber and a heat source outside that chamberheats the water to produce steam. The chamber is vented so as tomaintain the pressure within the cooking vessel at substantiallyatmospheric pressure. Such steam cooking devices may also employ thesteam at an elevated pressure as in the common "pressure cooker." U.S.Pat. No. 3,800,778 discloses a steam cooker with a valve and pumparrangement so that the pressure within the cooking vessel can bemaintained either above or below atmospheric pressure. However, thesereferences do not disclose steam cooking food products at 100% humidity,which, if prepared in such manner, would ensure that a skin will notdevelop on the outer surface of the food product during the cookingprocess. Moreover, there is no discussion of adding color or flavor tothe cook product.

International Publication No. WO84-02824 discloses an induction smokegenerator and method of producing natural smoke for use in cookingdevices. Therein, the apparatus and method for smoke treating foodproducts includes an inductively heated hollow member which is raised toa sufficiently high temperature so as to vaporize an injectedwater/smoke mixture. This vaporization occurs when the liquid smokemixture contacts the walls of the heatable hollow member. This method oftreating a food product in order to enhance the flavor of the foodproduct is well known.

Processes which are generally known for smoke treating or coloringvarious items including food products include the burning of wood chipsor saw dust which emitt natural smoke, atomizing liquid smokeconcentrate and mixing with water for spraying into a smoke room whichis kept at an elevated temperature and spraying liquid smoke onto aheated plate which vaporizes it into a gaseous state.

The natural, wood burn technique while potentially the best processes isgenerally inconsistent in its results. Additionally, this process isrelatively expensive compared to others. Food products flavored andcolored using natural wood burning techniques are relatively expensivein that utilizing such a technique is time consuming and requiresfrequent cleaning to remove ash and cinder from the associatedcombustion chambers.

A liquid smoke/water mix method reduces the inconsistency problem but isinadequate for treating certain food products due to the likelihood ofspotting of the product by water droplets formed in the treatingchamber.

Spraying liquid smoke onto a heated plate is a process which isfrequently utilized, however, this process eventually results in acaking of the plate and decreasing efficiency of the process as well asdown time required for cleaning the plate. Further, the powerrequirements are extremely high making it a less desirable approach inview of increasing energy costs.

Additionally, the Food and Drug Administration requires that foodproducts which are treated be labelled as including either artificialflavor or naturally smoked flavor. In the latter two examples set forthhereinabove, these products must be labeled as including artificialcolor and flavor. Clearly, it is a perceived marketing advantage to beable to label your product as being "naturally smoked".

One process which while not being a natural or wood burning technique isdisclosed in International Patent Publication No. 84/02824 and resultsin a process wherein the food product may be labeled as being naturallysmoked, however, this process requires a heat source in addition to theheat source used in cooking the food product as well as an atomizerwhich requires a control system so as to properly expel the liquidsmoke/water mixture into the hollow member.

Clearly, there is a need for a method and apparatus for cooking a meatproduct without resulting in an increase in processing cost whileallowing the food product to be labeled as "naturally smoked".

SUMMARY OF THE INVENTION

It is a primary object of the present invention to overcome theaforementioned shortcomings associated with the prior art.

Another object of the present invention is to provide an apparatus andmethod of producing a food product, wherein the food product is cookedand flavored in a manner so as to permit both "natural smoked flavor"and "natural coloring" to appear on the package label.

Yet another object of the present invention is to provide a meatproduct, and an apparatus and method of producing the same where themeat product is cooked within a chamber in which the amount of waterevaporation from the meat product can be regulated.

A still further object of the present invention is to provide a processand apparatus for cooking a food product and flavoring and coloring suchfood product without significantly increasing the production costs ofthe food product.

These as well as additional objects and advantages of the presentinvention are achieved by preparing a meat product wherein the meatproduct is heat treated to have little, if any, outer skin about itssurface. The meat product is placed inside of an air-tight chamber, inwhich the meat product is to be cooked. Steam is generated from a sourceof water and is introduced into the cooking chamber, wherein the steamheats the inside of the cooking chamber and serves as a heat transfermedia to heat the meat product. The steam and pressure within thecooking chamber are regulated so as to create an atmospheric humidity of100% within the chamber, so any water present within the meat isprevented from evaporating into the atmosphere of said cooking chamber.

The pressure within the cooking chamber can be reduced so as to producea controlled temperature steam from 160° to 212° F. to cook the meatproduct. Cooking the meat with a low temperature steam assists inpreventing the outer surface of the meat from cooking faster than theinside portion of the meat. Additionally, a flavored ingredient, such aliquid smoke, may be added to the water utilized in generating the steamin order to flavor the meat product being cooked.

In the case where a thin skin on the surface of the meat product isdesired, the pressure within the cooking chamber can be further reducedafter the steam has been heat treating the meat product for apredetermined time period. The reduction in pressure causes the boilingtemperature within the cooking chamber to drop, which allows anymoisture present on the surface of the meat product to boil off leavingbehind a protein and salt residue. The protein and salt residue, beingexposed to the heat within the cooking chamber, coagulates so that athin layer of skin will develop on the surface of the meat product.

The above noted method is carried out using an apparatus for cooking themeat product including an air-tight cooking chamber, a meat productsupport for supporting the meat product within the chamber, a source ofsteam and a control unit for maintaining a humidity level of 100% withinthe chamber. The apparatus further includes one of many devices forreducing the pressure within the chamber so as to control the cookingtemperature within the chamber, and preferably includes the addition ofliquid smoke to the source of steam so as to produce a food producthaving both enhanced flavor and color.

Using steam as the transfer media has many advantages because of theunique characteristics of steam. There are preferably three ways thatsteam can be used to transfer liquid smoke flavor and coloring to thefood product. First, when steam is used as the heat transfer media theliquid smoke could be added to the water used to generate the steam oradded to the steam directly. Because the food product is at a lowertemperature than the cooking chamber, the steam condenses on the surfaceof the food product thus depositing the smoke flavor and the color onthe surface of the food product. Different amounts of smoke flavor andcolor can be added to the food product being cooked by changing theamount of liquid smoke added to the steam. Second, in food processingplants where smokehouses are used to cook food products moisture isadded into the cooking chamber to raise the relative humidity. Therelative humidity is raised in the cooking chamber high enough to causethe dew point temperature to be higher than the surface temperature ofthe food product, this causes the moisture in the air to condense on thefood and add heat. The liquid smoke could be added to this steam andwhen it condenses on the surface of the food product would add smokeflavor and coloring to the food product. Third, some cookingapplications call for steam to be added to higher temperature baking androasting ovens. Liquid smoke added to this steam and would cause thesmoke flavor and color to be added to the products being cooked in theoven. Each of these processes would result in a smoked food productwhich can be marketed as a "naturally smoked" food product.

These as well as additional advantages of the present invention willbecome apparent from the following detailed description of theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of the steam cooker of the present invention.

FIG. 2 is a sectional view of a second embodiment of the steam cooker ofthe present invention.

FIG. 3 is a sectional view of a third embodiment of the steam cooker ofthe present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention provides for a new method of cooking a foodproduct. The food product of the present invention may be any meat whichtends to obtain a skin thereon during conventional cooking, includingpork, beef, and poultry. The food product may also be any other type offood product wherein it is desired to add smoked flavor or color to thefood product. The process of preparing the meat product without a skinformed thereon comprises the steps of placing a meat product into asteam cooker, circulating steam within the steam cooker to heat the meatproduct, and creating an atmospheric humidity of 100% within the steamcooker.

Once placed within the steam cooker, the meat product is exposed tosteam, which adds heat to the meat product in order to cook suchproduct. The steam cooker may be a conventional steam pressure cooker,in which a single meat product, such as a ham, may be placed therein andmay be used in the consumer's home. Alternatively, the steam cooker mayinclude a large-scale cooking chamber wherein a plurality of meatproducts may be placed, such as a smoke house. An air-tight chamber isformed within the steam cooker, so that the atmospheric environmentwithin the chamber may be controlled.

The amount of steam which is introduced into the chamber is regulated tomaintain the level of atmospheric humidity within the chamber at 100%.In addition to providing a humid environment within the chamber, thesteam is also used to cook the meat product by serving as a heattransfer media to heat the meat product. As the temperature of the meatproduct rises, some of the juice within the meat product is purged tothe surface. The juice, comprising water, animal protein, and salt,builds up on the surface during cooking and runs off of the meat producttaking the salt and protein with it. The water present in the juicecannot evaporate and thus leaves the protein and salt behind, becausethe steam environment of 100% humidity will not permit water toevaporate within the steam cooker. Unlike previous cooking methods wherewater is evaporated from the juices leaving a residual of protein andsalt behind to form a crust-like skin about the meat product, the meatproduct formed in accordance with the present invention does not leavethe protein and salt behind to be cooked and thus forms a skinless meatproduct. Therefore, cooking the meat product in atmospheric humidity of100% ensures that a skin will not develop on the surface of the meatproduct.

When exposing the meat product within the steam cooker to the hightemperatures associated with steam, namely 212° F., the outer surface ofthe meat product tends to cook quicker than the inner portion of themeat product. In order to ensure that the inner portion of the meatproduct is adequately cooked, the outer surface of the meat product isoften overcooked. Therefore, the process of cooking the meat product ofthe present invention may further include the step of placing the meatproduct into a reduced pressure steam cooker, wherein the meat productis subjected to a low temperature steam. Through lowering the pressurewithin the steam cooker, it is possible to obtain a steam having a lowertemperature. Subjecting the meat product to a low temperature steamensures that the meat product is more evenly cooked from its innerportion to its outer surface. This results in a higher quality meatproduct which is not cooked to different degrees within the meatproduct.

The pressure may be reduced within the steam cooker to regulate thetemperature therein within a range from 160° F. to 180° F. The pressurewithin the steam cooker is adjusted to provide the adequate cookingtemperature for the particular meat product being cooked. For instance,a low temperature steam of 165° F. is the optimal temperature whencooking a boneless ham. Depending upon the texture and thickness of themeat product being cooked, the temperature of the steam can be adjustedaccordingly.

Another step in the process of preparing the skinless meat product mayinclude the addition of a flavoring ingredient to the water which isused for generating the steam. Thereupon, the flavoring ingredient willbe carried by the steam in the steam cooker, such that, as the steam isheating the meat product, the flavoring ingredient will be disseminatedthroughout the steam and absorbed by the meat product. Therefore, themeat product can be flavored as it is being cooked. Any flavoringingredient which may suitably be added to the water and carried by thesteam may be used, such as liquid smoke, garlic, or onion flavoring.

In the instances when it is desirous to have a small amount of skin onthe meat product, such as with hotdogs and the like, a further step maybe added to the cooking process which creates a slight skin on the meatproduct. A small amount of skin could be formed by stopping the steamsupply and reducing the internal pressure within the chamber after themeat product is fully cooked, in order to cause the water contained inthe juice on the surface of the meat product to boil off leaving aprotein and salt residual behind. Therefore, after the meat product iscooked in an atmospheric humidity of 100% until it is fully cooked, thepressure within the chamber is reduced which, in turn, reduces theboiling temperature of water within the chamber. As the boilingtemperature drops within the chamber, the water present in the juice ofthe meat product is now capable of evaporating.

The pressure in the steam cooker could be reduced to produce a slightskin on the meat product through the use of vacuum pump. Theintroduction of a cold surface into the cooking chamber would alsoreduce the pressure therein. The cold surface could comprise a pipe coilextending through the cooking chamber, wherein cold water or arefrigerant is circulated through the pipe coil when a reduction inpressure is desired. The cold surface would cause the steam within thecooking chamber to condense and thereby reduce the pressure, resultingin the water on the surface of the meat product boiling off.Alternatively, a spray of cold water into the cooking chamber would alsoachieve a similar result to the addition of a cold surface hereindescribed.

While the above embodiments for reducing the pressure within the cookingchamber are described above, it is understood that any method ofreducing the pressure within the cooking chamber would suffice inallowing the moisture from the meat product to evaporate.

Referring to FIG. 1, the apparatus of the present invention will now beset forth. The meat product may be positioned within steam cooker 2 ontoa cooking rack 4. The cooking rack 4 is supported on its ends byprotrusions 6 extending from the inner walls 8 of cooking chamber 10.When it is desirous to cook a plurality of meat products within cookingchamber 10, a series of cooking racks 4 may be positioned within thecooking chamber 10, while being spaced apart from each other a distanceat least equivalent to the size of the meat product being cooked. In analternative arrangement, the meat product could be hung within cookingchamber 10, such as by a hook or the like or placed on carts andmanipulated within a large smoke house or oven.

The steam used for transferring heat to the meat product is generated byheating the water 12 within cooking chamber 10 to its boiling point. Thewater 12 is introduced into the cooking chamber 10 through a valve 14,which connects the inner cooking chamber 10 to a source of water. Thesteam used for cooking may alternatively be generated outside of thecooking chamber 10 and introduced into the cooking chamber 10 throughvalve 14. The amount of steam to be generated or introduced into cookingchamber 10 is controlled by thermostat 16 which determines thetemperature within cooking chamber 10.

A vacuum pump 18 is provided for selectively removing air from withincooking chamber 10 and reducing the pressure therein. Reducing thepressure within the cooking chamber 10 thus reduces the temperature ofthe steam and eliminates overcooking which causes the meat product tobecome tough. The ideal temperature for cooking beef is approximately155° Fahrenheit while the ideal temperature for chicken and pork isapproximately 170° Fahrenheit. Consequently it is desirable to maintainthe cooking temperature within the cooking chamber 10 in the range of150° to 180° Fahrenheit. This can be accomplished by controlling thepressure within the cooking chamber 10.

The vacuum pump 18 may also be utilized for instantaneously reducing theinternal pressure within the cooking chamber 10 enough to cause thewater on the surface of the meat product to boil off leaving a skinbehind. The small amount of skin is formed by stopping the steam supplyand reducing the internal pressure within the chamber using vacuum pump18 after the meat product is cooked. This results in the lowering theboiling temperature within cooking chamber 10 to below the boilingtemperature of water on the surface of the meat product. Thus, the watercontained in the juice on the surface of the meat product will boil offleaving a protein and salt residual behind.

Referring now to FIG. 2, an alternative embodiment of the presentinvention is illustrated, wherein a piping tube 20 is positioned withincooking chamber 10 in order to reduce the pressure therein. The pipingtube 20 has a refrigerant, such as freon or cold water, circulatedtherethrough by a circulating pump 22. When the refrigerant or coldwater is circulated through piping tube 20, a cold surface within thecooking chamber 10 is created which causes the steam within the cookingchamber 10 to condense, thereby reducing the pressure within the cookingchamber 10. When the supply of steam into cooking chamber 10 has ceasedand the refrigerant is introduced into piping tube 20, the for reductionin pressure will result in a drop in the boiling temperature causing themoisture to boil off the surface of the meat product which then forms askin thereon. Therefore, piping tube 20 may used to achieve the sameresult as vacuum pump 18 in controlling the pressure within the cookingchamber 10.

Referring now to FIG. 3, the pressure within cooking chamber 10 may alsobe instantaneously reduced by a spray of cold water into the chamberthrough injection valve 24. Towards the end of the cooking cycle for themeat product, the cold water spray is introduced into the cookingchamber which causes the steam to condense. Thus, the boilingtemperature within the cooking chamber 10 will fall and the moisture onthe surface of the meat product will boil off leaving the protein andsalt residue behind.

A further aspect of the present invention includes using steam as thetransfer media for transferring flavoring and coloring to the foodproduct. Using steam as the transfer media has many advantages becauseof the unique characteristics of steam. There are preferably three waysthat steam can be used to transfer liquid smoke flavor and coloring tothe food product. First, when steam is used as the heat transfer mediathe liquid smoke is to be added to the water used to generate the steamor added to the steam directly. Because the food product is at a lowertemperature than the cooking chamber, the steam condenses on the surfaceof the food product thus depositing the smoke flavor and the smoke coloron the surface of the food product. Different amounts of smoke flavorand smoke color can be added to the food product being cooked bychanging the amount of liquid smoke added to the steam. Second, in foodprocessing plants where smokehouses are used to cook food products,moisture is added into the cooking chamber to raise the relativehumidity, The relative humidity is raised in the cooking chamber highenough to cause the dew point temperature to be higher than the surfacetemperature of the food product, this causes the moisture in the air tocondense on the food and add heat. The liquid smoke is to be added tothis steam and when it condenses on the surface of the food product willadd the smoke flavor and coloring to the food product. Third, somecooking applications call for steam to be added to higher temperaturebaking and roasting ovens. Liquid smoke, added to this steam, wouldcause the smoke flavor and color to be added to the products beingcooked in the oven. Each of these processes will result in a smoked foodproduct which can be marketed as a "naturally smoked" food product.

As can be seen from the foregoing, a meat product prepared in accordancewith the present invention will provide a product which is cookedwithout forming a skin about an outer periphery thereof. Moreover, byregulating the pressure within the steam cooking chamber, thetemperature of the steam in the cooking chamber may be controlled which,in turn, allows the amount of water evaporation from the surface of themeat product to be controlled, thus allowing the formation of a skin onthe surface of the meat product to be regulated to its desired level.Further, a food product having a flavor and color additive which stillpermits the food product to be marketed as "naturally smoked" and"naturally colored" is obtained.

While the present invention has been described with reference to thepreferred embodiment, it will be appreciated by those skilled in the artthat the invention may be practiced otherwise then as specificallydescribed herein without departing from the spirit and scope of theinvention. It is, therefore, to be understood that the spirit and scopeof the invention be limited only by the appended claims.

What is claimed is:
 1. A method for treating a food product comprisingthe steps of:placing the food product into an air-tight cooking chamber;providing a source of water communicating with said chamber; adding afood product enhancing additive to said source of water; generatingsteam from said source of water, said steam including said food productenhancing additive; introducing said steam carrying said food productenhancing additive into said air-tight cooking chamber containing thefood product; reducing the steam pressure within said cooking chamber toproduce a low temperature steam in the range of 150° to 180° F., andcontacting said food product with said low temperature steam and saidlow temperature food product enhancing additive thereby heat treatingsaid food product with said low temperature steam and said food productenhancing additive.
 2. The method as defined in claim 1, wherein saidfood product enhancing additive includes a flavoring ingredient, saidflavoring ingredient adding a particular flavor to said food product assaid food product is being treated with said steam.
 3. The method asdefined in claim 2, wherein said flavoring ingredient comprises liquidsmoke.
 4. The method as defined in claim 2, wherein said food productenhancing additive enhances the color of said food product.
 5. Themethod as defined in claim 1, further comprising the step of reducingthe steam pressure within said cooking chamber after said steam has beenheat treating said food product for a predetermined time period so thatsaid reduction in pressure allows the moisture to boil off of thesurface of said food product so that a thin layer of skin will developthereon.
 6. A method for treating a food product comprising the stepsof:placing the food product into an air-tight cooking chamber; providinga source of steam communicating with said chamber; adding a food productenhancing additive to said source of steam; introducing said steamcarrying said food product enhancing additive into said air-tightcooking chamber containing the food product; reducing the steam pressurewithin said cooking chamber to produce a low temperature steam in therange of 150° to 180° F., and contacting said food product with said lowtemperature steam and said food product enhancing additive thereby heattreating said food product with said low temperature steam and said foodproduct enhancing additive.
 7. The method as defined in claim 6, whereinsaid food product enhancing additive includes a flavoring ingredient,said flavoring ingredient adding a particular flavor to said foodproduct as said food product is being treated with said steam.
 8. Themethod as defined in claim 7, wherein said flavoring ingredientcomprises liquid smoke.
 9. The method as defined in claim 6, whereinsaid food product enhancing additive enhances the color of said foodproduct.